Implantable medical devices (IMDs) include, among other things, cardiac function management (CFM) devices such as implantable pacemakers, implantable cardioverter defibrillators (ICDs), cardiac resynchronization therapy devices (CRTs), and devices that include a combination of such capabilities. The devices can be used to treat patients or subjects using electrical or other therapy, or to aid a physician or caregiver in patient diagnosis through internal monitoring of a patient's condition. Other examples of IMDs include implantable diagnostic devices, implantable drug delivery systems, or implantable devices with neural or neuro-stimulation capability. The devices may include one or more electrodes in communication with one or more sense amplifiers to monitor electrical heart activity within a patient, and often include one or more sensors to monitor one or more other internal patient parameters. Neural stimulation devices can be used to treat hypertension and respiratory disorders.